Golf is enjoyed by a wide variety of players—players of different genders, and players of dramatically different ages and skill levels. Golf is somewhat unique in the sporting world in that such diverse collections of players can play together in golf outings or events, even in direct competition with one another (e.g., using handicapped scoring, different tee boxes, etc.), and still enjoy the golf outing or competition. These factors, together with increased golf programming on television (e.g., golf tournaments, golf news, golf history, and/or other golf programming) and the rise of well known golf superstars, at least in part, have increased golf's popularity in recent years, both in the United States and across the world.
Golfers at all skill levels seek to improve their performance, lower their golf scores, and reach that next performance “level.” Manufacturers of all types of golf equipment have responded to these demands, and recent years have seen dramatic changes and improvements in golf equipment. For example, a wide range of different golf ball models now are available, with some balls designed to fly farther and straighter, provide higher or flatter trajectory, provide more spin, control, and feel (particularly around the greens), etc.
Being the sole instrument that sets a golf ball in motion during play, the golf club also has been the subject of much technological research and advancement in recent years. For example, the market has seen improvements in golf club heads, shafts, and grips in recent years. Additionally, other technological advancements have been made in an effort to better match the various elements of the golf club and characteristics of a golf ball to a particular user's swing features or characteristics (e.g., club fitting technology, ball launch angle measurement technology, etc.).
Despite the various technological improvements, golf remains a difficult game to play at a high level. For a golf ball to reliably fly straight and in the desired direction, a golf club should meet the golf ball square (or substantially square) to the desired target path. Moreover, the golf club should meet the golf ball at or close to a desired location on the club head face (i.e., on or near a “desired” or “optimal” ball contact location) to reliably fly straight, in the desired direction, and for a desired distance. Off-center hits that deviate from squared contact and/or are located away from the club's desired ball contact location may tend to “twist” the club face when it contacts the ball, thereby sending the ball in the wrong direction, often imparting undesired hook or slice spin, and/or robbing the shot of distance. Thus, when the club face is not square at the point of engagement, the golf ball may fly in an unintended direction and/or may follow a route that curves left or right, ball flights that are often referred to as “pulls,” “pushes,” “draws,” “fades,” “hooks,” or “slices,” or may exhibit more boring or climbing trajectories.
The energy and velocity transferred to the ball by a golf club may be related, at least in part, to the flexibility of the club face at the point of contact, and can be expressed using a measurement called “coefficient of restitution” (or “COR”). The maximum COR for golf club heads is currently limited by the USGA at 0.83. Generally, a club head will have an area of highest response relative to other areas of the face, such as having the highest COR, which imparts the greatest energy and velocity to the ball, and this area is typically positioned at the center of the face. In one example, the area of highest response may have a COR that is equal to the prevailing USGA limit (e.g. 0.83), which may change over time. However, because golf clubs are typically designed to contact the ball at or around the center of the face, off-center hits may result in less energy being transferred to the ball, decreasing the distance of the shot. The COR at a specific location on the club head can be related to the modulus of elasticity at the impact location, as well as the modulus of other areas of the face spaced away from the impact location. Similarly, the contact time between the ball and the face during impact can affect energy transfer. Generally, a more flexible (lower modulus) face will produce higher contact times, resulting in greater energy transfer. The contact time is currently limited by the USGA at 257 μs, according to the USGA Characteristic Time (CT) test. Club head features that can increase the energy transferred to a ball during impact can be advantageous.
It is common for professional golfers and other experienced golfers to have higher swing speeds (i.e., the speed of the club head at or around impact with the ball) than less experienced golfers. Many club heads are designed to deliver optimal performance at higher swing speeds, and may offer less optimal performance at lower swing speeds. Accordingly, club head features that can improve performance at lower swing speeds can prove to be advantageous for use by less experienced golfers.
The present device and method are provided to address the problems discussed above and other problems, and to provide advantages and aspects not provided by prior ball striking devices of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.